Yes, this is exactly right. With IPV6 you can give explicit instructions to open up a port because you know what port to open up. The frustrating part is that

Yes, this is exactly right. With IPV6 you can give explicit instructions to open up a port because you know what port to open up. The frustrating part is that none of this should be a problem. It's just that lots and lots of routers don't follow the specs properly. Here it is 2017 and you still can't reliably punch a hole in a firewall.